JPH04191837A - Liquid crystal exposure device - Google Patents

Abstract

PURPOSE:To output a pure white color which is not mixed with the other color by adding the exposure of a white color area by white color by removing the filters of three colors of red, green and blue after the exposure of the respective colors is executed by using the filters of three colors. CONSTITUTION:Image data inputted from the outside is separated to the respective crystal display element(LCD) shutter 7 based on respective gradation data. Then, the images thereof are formed on a photosensitive recording medium 20 by using a condensing means 8 and the exposure of the respective colors is executed by using the respective color filters of red, green and blue 5. After the exposure of three colors is finished, the place of the data where a value obtained by adding the data of red, green and blue is identical to the total count value of the maximum proper exposure of the respective colors becomes the white color of 100%. Therefore, the exposure for the white color is executed by opening the liquid crystal picture element of the shutter 7 at the part by an LCD controller 14, removing the filters 5 to the outside of an optical path and making the white color light incident on. Thus, the white color of 100% which is not mixed with the other color is outputted and the quality of an image is improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a liquid crystal exposure device used in an image recording device for color printing out color images and character data based on video signals, etc. The present invention relates to a liquid crystal exposure device that improves image quality by improving output of whiteness of a portion.

[Conventional technology]

In recent years, various liquid crystal display elements (LCDs) have been developed that utilize various electro-optic effects in liquid crystals to switch between light transmission and light blocking.
) shutter has been developed.

Here, among the LCD shutters, a twisted nematic (TN) type LCD shutter will be explained. This TN type LCD shutter is made up of a plurality of liquid crystal light modulation elements arranged, and in each liquid crystal light modulation element, the liquid crystal is formed by two transparent electrode substrates (outside) and two sheets having uniform linear grooves. It is sandwiched between an alignment film (inner side). When no voltage is applied between the transparent electrodes, the liquid crystal molecules assume a specific alignment state according to the force regulated by the grooves of the alignment film. In this case, the groove directions of the above two alignment films are 90 degrees from each other.
Because of the degree of misalignment, the liquid crystal molecules exhibit a twisted structure in the long axis direction of the molecules, and the alignment of the liquid crystal molecules is twisted by 90 degrees between both alignment films. When the TN type liquid crystal light modulation element in this state is sandwiched between two polarizing plates whose polarization directions are perpendicular to each other, and a light beam is incident from one of the polarizing plates, the light beam becomes linearly polarized light at the first polarizing plate. While the second linearly polarized light travels through the liquid crystal, the polarization direction of the linearly polarized light is rotated by 90 degrees due to the birefringence of the liquid crystal molecules and the above-described 90 degree twisted alignment structure. As a result, the polarization direction of the linearly polarized light matches the polarization direction of the other polarizing plates, and the linearly polarized light is emitted as is. However, when a voltage is applied between the transparent electrodes,
Since the liquid crystal molecules are forcibly aligned in the direction of the electric field, the above-mentioned 90 degree twisted alignment structure of the liquid crystal molecules is not formed. Therefore, the linearly polarized light incident from one polarizing plate reaches the other polarizing plate without rotation of the polarization direction, and when it is output, the polarization direction of the linearly polarized light and the polarization direction of the other polarizing plate are orthogonal and the light is blocked. be done. A liquid crystal light modulation element that blocks light when a voltage is applied is called normally white, and a liquid crystal light modulation element that transmits light when a voltage is applied when the two polarizing plates have the same polarization direction is called normally black.

The switching between light transmission and light blocking as described above is performed by applying a voltage between the transparent electrodes. By arranging a plurality of liquid crystal light modulation elements, a shutter with high response speed becomes possible.

Focusing on the characteristics of such LCD shutters, we
Various liquid crystal exposure devices using shutters have been developed. Normally, in such a liquid crystal exposure device, red, green, and blue color data are displayed on the same liquid crystal pixel separately on an LCD shutter based on gradation data, and the images are transferred onto photosensitive paper using an imaging lens. A full-color print is performed on each pixel by forming an image and using a three-exposure method using red, green, and blue color filters.

[Problem to be solved by the invention]

However, with the above-mentioned liquid crystal exposure device, the maximum appropriate exposure amount for each of red, green, and blue is determined by the sensitivity of the photosensitive paper, and the exposure of the three colors is added at this maximum appropriate exposure amount. There was a problem in that even if the colors were combined, a 100% white color would be produced, but the white color would be mixed with other colors.

The present invention has been made in view of the above-mentioned circumstances, and provides a liquid crystal exposure device that enables high-quality image formation by outputting 100% white without any mixture of other colors. The purpose is to

[Means to solve the problem]

In order to achieve such an object, the present invention provides a liquid crystal exposure apparatus that exposes a photosensitive recording medium based on an image signal, the liquid crystal exposure apparatus comprising: a light source; an LCD shutter comprising a plurality of liquid crystal light modulation elements; a filter that separates the light from the light source into three colors of red, green, and blue; a condensing means for condensing the light from the light source; and a condensing means for condensing the light from the light source, and the white light from the light source is transferred to the photosensitive recording without passing through the filter A filter driving device for moving the filter out of the optical path so that the medium is irradiated, and a mask control means for controlling the projection range of the LCD shutter so that only the white exposure range of the photosensitive recording medium is exposed. It was structured like this.

[Effect]

Image data input from the outside is separated into red, green, and blue colors, and displayed on the LCD shutter based on the gradation data of each color. Then, the image is formed on a photosensitive recording medium using a condensing means, and each color is exposed using red, green, and blue color filters. After the exposure of the three colors is completed, add the red, green, and blue data, and the data location where the value is the same as the total value of the maximum appropriate exposure amount for each color is 1.
Since the color is 00% white, the LCD controller opens only the liquid crystal pixels of the LCD shutter in that area, and the filter drive device removes the filter from the optical path to allow white light to enter and perform white exposure. Therefore, it is possible to output 100% white color without mixing with other colors, and image quality can be improved.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

First, an example of an image recording apparatus using the liquid crystal exposure apparatus of the present invention will be described. FIG. 1 is a schematic diagram of an image recording apparatus using a liquid crystal exposure apparatus of the present invention. In FIG. 1, an image recording device 1 includes a liquid crystal exposure device 2, and is configured such that a long microcapsule paper 20 as a photosensitive recording medium is conveyed through an exposure area 17 below the liquid crystal exposure device 2. There is.

The liquid crystal exposure device 2 includes a halogen lamp 3 as a light source and a reflector 3 that reflects the light emitted from the halogen lamp 3.
a, light emitted from the halogen lamp 3 and reflector 3a
a condenser lens 3b that converts the reflected light from the lens into parallel light, an infrared cut filter 4 that cuts infrared rays, and a filter that separates the light that has passed through the condenser lens 3b and the infrared cut filter 4 into a single color of red, green, or blue. A filter unit 5 consisting of 5R, 5G, and 5B, a filter drive device 9 for moving the filter out of the optical path, and an LCD shutter 7 having a deformed curved surface for aberration correction.
, an LCD controller 14 as a mask control means for controlling the projection range of the LCD shutter 7, and an imaging lens 8. A video RAMI 3, an A/D conversion circuit 12, and a video I/F circuit 11 are connected to the LCD controller 14, and the operations of these mechanisms will be described later.

The microcapsule paper 20 has a plurality of microcapsules coated on the surface of a long support, and the microcapsules contain a dye precursor that reacts with a color developer described later. And unexposed microcapsule paper 20
is mounted in a light-shielding cartridge 21 in a state where it is wound around a cartridge shaft 22. Further, on the right side of this cartridge 21, feed rollers 23, 23 for conveying the microcapsule paper 20 are arranged.

The microcapsule paper 20 exposed in the lower exposure area 17 of the liquid crystal exposure device 2 is placed on the pressure roller 30a in a state where it is overlapped with the color developer paper 35.

30b for pressure development. Thereafter, the microcapsule paper 20 separated from the developer paper 35 is wound around a cartridge shaft 27 disposed within the cartridge 26.

Above the pressure rollers 30a and 30b, a plurality of color developing papers 3
A cassette 37 containing cassettes 5 and 5 is installed. A half-moon roller 41 is disposed at the upper left of the cassette 37, and the rotation of the half-moon roller 41 feeds out the color developing paper 35 one by one between paper feed rollers 42, 42. The fed out developing paper 35 is fed to the feed guide 4
3, and is conveyed to pressure rollers 30a and 30b at a timing such that the leading edge of the color developer paper 35 and the leading edge of the latent image on the microcapsule paper 20 are aligned.

The color developer paper 35 has a color developer coated on the surface of the support.
The details of how the color is developed by reacting with the dye precursor encapsulated in the microcapsules of the microcapsule paper 20 are described in US Pat. No. 4,399,209 and will not be described here.

A heat fixing device 50 is arranged on the right side of the pressure rollers 30a and 30b, a heater 51 is provided inside this heat fixing device 50, and a conveyor belt 52 for conveying the color developer paper 35 is provided at the bottom. is installed.

Next, the operation of the image recording device 1 will be explained.

Data output from the outside is input to the image recording apparatus 1 through the video r/f circuit 11. The data is digitized by the A/D conversion circuit 12, separated into red (R), green (G), and blue (B) and stored in the video RAM 13. Then, the gradation data of each color is sent to the LCD controller 14, and an image is formed on the LCD shutter 7.

When a print start key (not shown) is pressed, an image corresponding to a red (R) image signal inputted from the outside is first displayed on the LCD shutter 7. Next, the halogen lamp 3 that is the light source is turned on, and the reflector 3
The reflected light from a and the emitted light from the halogen lamp 3 are made into parallel light by a condenser lens 3b, pass through an infrared cut filter 4, are made into red light by a red filter 5R, and enter the LCD shutter 7. This LCD
The shutter 7 is connected to the LCD according to the red (R) image signal.
It is controlled by a controller (mask control means) 14. The light transmitted through each pixel (liquid crystal light modulation element) of the LCD shutter 7 is focused by the imaging lens 8 and irradiated onto the microcapsule paper 20, completing the red exposure.

The above is the red exposure shown in Fig. 2. When this red exposure is finished, the red filter 5R is replaced with the green filter 5G, and the red (R) image signal of the LCD shutter 7 becomes the green (G) image signal. As shown in FIG. 3, green light is exposed in the same process as red light. As for the blue color, as shown in FIG. 4, exposure is performed in accordance with the image signal for blue (B), and the exposure of the three colors is completed.

In the liquid crystal exposure apparatus 2 of the present invention, next, each video RA
Add the RlG and B color data stored in MI 3. Since the data point where the value is the same as the total value of the maximum exposure amount of each color is 100% white, the LCD controller 14 causes the LCD shutter 7 to display the liquid crystal of that portion as shown in FIG. A mask is constructed by leaving only the pixel open and leaving the other peripheral liquid crystal pixels in a light-blocking state. Thereafter, the filter unit 5 is removed from the optical path by driving the filter drive device 9, and the filter unit 5 is removed from the optical path.
Exposure for white color is performed by inputting white light.

L displaying pixels with only this 100% white information
By exposing the CD shutter 7 to white light containing RSG and B wavelengths, pure white can be output. Furthermore, even if this white part is exposed to too much light, there is no problem even if the other color areas are overexposed because the light is blocked by the liquid crystal shutter. In addition, FIG. 6 shows R(
The relationship between exposure of each color (red), G (green), B (blue), and W (white) is shown. As a result, a latent color image is formed on the microcapsule paper 20. During this time, the microcapsule paper 20 stops being conveyed and is in a stopped state.

When the exposure of R, G, and 83 colors described above and the subsequent white exposure are completed, the microcapsule paper 20 is conveyed toward the pressure rollers 30a and 30b by the driving force of the feed roller 23 and the take-up roller 27. On the other hand, developer paper 35
is fed one sheet at a time by a half-moon roller 41, and is moved to pressure rollers 30a and 30b by a paper feed roller 42 and a paper feed guide 43.
transported to. Then, the pressure roller 30a is placed in a state where the exposed surface of the microcapsule paper 20 and the color developer coated surface of the color developer paper 35 are superimposed so as to be in contact with each other.

30b, and the image is transferred onto the color developing paper 35. The color developing paper 35 is further conveyed by a conveyor belt 52 while being accelerated in color development by a heater 51 of a heat fixing device 50, and is output as an image.

The present invention is not limited to the above-described embodiments, and various changes can be made without departing from the spirit thereof. For example, although a halogen lamp is used as the light source in this embodiment, it is also possible to use a metal halide lamp or other similar lamp. Furthermore, the order in which the color filters are replaced is not limited to R-G-B.

〔Effect of the invention〕

As detailed above, according to the present invention, the three colors of red, green, and blue
After exposing each color using a color filter, the filter is removed and the white area is exposed using white light, thereby creating a liquid crystal exposure device that can output 100% white without mixing with other colors. This has the effect that it can be provided.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an image recording device using the liquid crystal exposure device of the present invention, Fig. 2 shows red exposure using red (R) data, and Fig. 3 shows green exposure using green (G) data. 4 is a diagram showing blue exposure using blue (B) data, and FIG. 5 is a diagram showing R and G. FIG. 6 is a diagram showing additional white exposure by adding B data, and FIG. 6 is a diagram showing a state in which color output is performed. DESCRIPTION OF SYMBOLS 1... Image recording device, 2... Liquid crystal exposure device, 3... Halogen lamp, 5R, 5G, 5B... Filter, 7... LCD shutter 1 9... Filter drive device, 14.・・LCD controller (7 screen control means), 2
0...Microcapsule paper (g optical recording medium). Applicant's agent Yasushi Ishikawa Figure 5 Figure 6

Claims (1)

[Claims] A liquid crystal exposure device that exposes a photosensitive recording medium based on an image signal, the liquid crystal exposure device comprising: a light source; an LCD shutter comprising a plurality of liquid crystal light modulation elements; green,
a filter that separates the light into three colors of blue; a condensing means for condensing the light from the light source; and a condensing means for condensing the light from the light source, and the filter so that the white light from the light source is irradiated onto the photosensitive recording medium without passing through the filter. A liquid crystal exposure device comprising: a filter driving device for moving out of the optical path; and a mask control means for controlling the projection range of the LCD shutter so that only the white exposure range of the photosensitive recording medium is exposed. .